Expression Analysis of RAD51, Caspase-3, and BAX Proteins Associated with Apoptosis and DNA Repair in Central Nervous System (CNS) Tumors

Introduction and Aim: Tumors of the central nervous system (CNS) are associated with high levels of morbidity and mortality. This study investigated the clinicopathological relevance and prognostic utility of apoptosis- and DNA repair–associated biomarkers, including Caspase-3, BAX, and RAD51, in CNS malignancies.

Materials and Methods: A retrospective cohort of 148 patients with intracranial tumors was analyzed. Immunohistochemical (IHC) staining was performed to assess and compare the expression patterns of Caspase-3, BAX, and RAD51 in tumor specimens and adjacent non-neoplastic brain tissues. Associations between biomarker expression, clinicopathological parameters, and postoperative survival were evaluated using univariate and multivariable logistic regression analyses.

Results: BAX and RAD51 were significantly overexpressed in tumor tissues compared with normal brain tissue (p < 0.001), while Caspase-3 showed a relatively minor but statistically significant difference (p = 0.03). In multivariable analysis, advanced tumor grade (p < 0.001) and older age (p = 0.0506) emerged as independent predictors of postoperative mortality. However, none of the investigated biomarkers retained independent prognostic significance after adjustment for confounding factors.

Conclusion and Clinical Relevance: Although BAX and RAD51 are significantly dysregulated in CNS tumors, their expression does not provide additional prognostic value beyond established clinicopathological variables. Histological grade remains the most robust determinant of patient survival following surgery.

Keywords: Central nervous system tumors; Caspase-3; BAX; RAD51; biomarkers; survival